JP2012112745A - Lighting fixture with doppler sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lighting fixture equipped with a Doppler sensor in which a radiation noise generated by a fluorescent lamp is not easily emitted in a Doppler sensor.SOLUTION: A virtual plane including a surface facing to a fluorescent lamp 2 in a tabular cover 4 is defined as a first plane P1. In a cross-section orthogonal to the central axis O of a light-emitting part of the fluorescent lamp 2 and in a border line of a detection range of a Doppler sensor 5 in a cross-section including a transmitting/receiving part 51 of the Doppler sensor 5, an angle θ formed by a border line 52 on the side close to the fluorescent lamp 2 and a perpendicular line to the first plane P1, a distance d between the central axis O and the first plane P1, a distance y between the first plane P1 and the transmitting/receiving part 51 and a distance x between a second plane P2 which includes the central axis O and is orthogonal to the first plane P1 and transmitting/receiving part 51 satisfy the conditions of the following expression.

Description

  The present invention relates to a lighting fixture with a Doppler sensor.

  2. Description of the Related Art Conventionally, there has been provided a luminaire with a Doppler sensor that detects a human body with a Doppler sensor and switches the light source on and off according to the detection of the human body (see, for example, Patent Document 1). In this type of luminaire, useless power consumption due to the user forgetting to turn off the light source can be suppressed as compared with the case where the light source is turned on / off manually.

  The Doppler sensor described above transmits (irradiates) a radio wave (transmission wave) such as a millimeter wave to a detection range, receives a radio wave (reflected wave) reflected in the detection range, and obtains an electric wave obtained by the reception. The signal is mixed (multiplied) with an electric signal having the same frequency as the transmission wave, and a Doppler signal is obtained by extracting a frequency band component corresponding to the moving speed of the human body from the obtained electric signal. By comparing the amplitude of the Doppler signal with a predetermined determination threshold, it is possible to determine the presence or absence of a human body within the detection range.

  Other sensors that detect the human body include, for example, a heat ray sensor (so-called PIR sensor) that detects heat rays emitted from the human body. Compared with a heat ray sensor, the Doppler sensor has an advantage that it is less susceptible to an environmental temperature change and an advantage that it can detect a human body at a relatively long distance. Due to the above advantages, the Doppler sensor is suitable for use in a place where the temperature changes more rapidly than in the case of a heat ray sensor, or for a usage pattern in which the Doppler sensor is attached to the ceiling in a building with a high ceiling.

JP 2009-168778 A

  By the way, as said lighting fixture, as shown in FIG.3 and FIG.4, while using the straight tube | pipe type fluorescent lamp 2 which has a column-shaped light emission part as a light source, this fluorescent lamp 2 is hold | maintained and a wall surface etc. There is a lighting fixture 1 having a fixture main body 3 fixed to a construction surface (not shown) and a cover 4 for sandwiching the fluorescent lamp 2 between the fixture main body 3.

  Specifically, the fluorescent lamp 2 is a hot cathode type discharge lamp that is lit with AC power. Since such a fluorescent lamp 2 is well known, detailed illustration and description thereof will be omitted.

  Hereinafter, the lighting fixture 1 of FIG.3 and FIG.4 is demonstrated concretely.

  The fixture body 3 has an elongated rectangular parallelepiped shape, and holds a lighting device (not shown) for lighting the fluorescent lamp 2 and a socket (not shown) electrically connected to the lighting device. As the lighting device, for example, a known copper iron ballast or electronic ballast can be used. The lighting device determines the presence or absence of a human body within the detection range based on the output of the Doppler sensor 5, and turns on the fluorescent lamp 2 if it is determined that a human body exists within the detection range while the fluorescent lamp 2 is turned off. When the duration of the state in which it is determined that no human body exists within the detection range while the lamp 2 is lit reaches a predetermined control delay time, the fluorescent lamp 2 is turned off. In addition, two sockets are held in total, one at each end in the longitudinal direction of the fixture body 3 corresponding to a base (not shown) provided at each end in the axial direction of the light emitting portion of the fluorescent lamp 2. Each is detachably coupled to one cap. That is, in the state where the socket is coupled to each base, electrical connection between the fluorescent lamp 2 and the lighting device is achieved through the socket. In this state, the longitudinal direction of the fixture body 3 and the axis of the light emitting portion of the fluorescent lamp 2 are achieved. The direction matches. Since the lighting device and the socket as described above can be realized by a well-known technique, detailed illustration and description are omitted.

  The cover 4 is made of a light-transmitting material such as glass, for example, and covers the fluorescent lamp 2 when viewed from the direction illuminated by the fluorescent lamp 2 (upward in FIG. 4). The purpose of providing the cover 4 includes, for example, protecting the fluorescent lamp 2 and improving the appearance by diffusing the light of the fluorescent lamp 2. The cover 4 is, for example, an elongated rectangular flat plate, and is connected to the instrument main body 3 via an appropriate fitting or the like with a gap between the instrument main body 3 and the longitudinal direction aligned with the longitudinal direction of the instrument main body 3. . That is, the surface of the cover 4 facing the fluorescent lamp 2 is parallel to the central axis of the light emitting part of the fluorescent lamp 2.

  In addition, a Doppler sensor 5 is fixed to the instrument body 3. The Doppler sensor 5 is disposed between the instrument body 3 and the cover 4. In the Doppler sensor 5, a transmission / reception unit (upper surface in FIG. 4) 51 that is a transmission unit that emits radio waves and that also receives a radio wave is directed to the cover 4, and the detection range is, for example, the transmission / reception unit 51 as a vertex. It has a truncated cone shape and penetrates the cover 4. Since the Doppler sensor 5 can also be realized by a well-known technique, detailed illustration and description are omitted.

  However, when the detection range of the Doppler sensor 5 penetrates the cover as described above, radiation noise generated by the fluorescent lamp 2 is reflected by the cover 4 and incident on the transmission / reception unit 51 as indicated by an arrow A1 in FIG. This sometimes caused erroneous determination.

  This invention is made | formed in view of the said reason, The objective is to provide the lighting fixture with a Doppler sensor in which the radiation noise which generate | occur | produced with the fluorescent lamp is hard to inject into a Doppler sensor.

  The lighting fixture with a Doppler sensor according to the present invention includes a flat cover and a cylindrical light-emitting part, and is a straight line disposed on one side in the thickness direction of the cover with the central axis of the light-emitting part being parallel to the cover. Radio waves incident from a predetermined detection range including a tube-type fluorescent lamp and a first plane including the one surface of the cover on the same side as the fluorescent lamp and including a part of the first plane A Doppler sensor having a receiving unit for receiving the light, and a cross section perpendicular to the central axis of the light emitting unit of the fluorescent lamp, which is a boundary line of the detection range in a cross section including the receiving unit, and is close to the fluorescent lamp An angle θ formed by a boundary line on the side and a perpendicular of the first plane, a distance d between the central axis of the light emitting unit and the first plane, a radius r of the light emitting unit, the first plane, and the reception Including the distance y to the light emitting part and the central axis of the light emitting part A second plane perpendicular to the first plane and the distance x between the receiving unit, the following equation

It satisfies the following conditions.

  In this lighting fixture with a Doppler sensor, it is desirable that at least a part of the Doppler sensor does not overlap the cover as viewed from the thickness direction of the cover.

  Furthermore, in this lighting fixture with a Doppler sensor, the Doppler sensor may be arranged in the vicinity of the central portion in the axial direction of the light emitting portion of the fluorescent lamp.

  In this lighting fixture with a Doppler sensor, y> d may be satisfied.

  Furthermore, in this lighting fixture with a Doppler sensor, the Doppler sensor may be fixed and used so as to be positioned below the fluorescent lamp.

  According to the present invention, since the radiation noise generated in the fluorescent lamp does not enter the Doppler sensor at least by one reflection at the cover, the radiation noise generated in the fluorescent lamp does not easily enter the Doppler sensor.

It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows the example of a change same as the above. It is a perspective view which shows an example of the lighting fixture with a Doppler sensor. It is explanatory drawing which shows the subject of a prior art example.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  Since the basic configuration of this embodiment is the same as that of the lighting fixture 1 shown in FIGS. 3 and 4, the corresponding components are denoted by the same reference numerals, and detailed illustration and description are omitted.

  In the present embodiment, as shown in FIG. 1, the fluorescent lamp 2, the cover 4, and the Doppler sensor 5 are arranged so that radiation noise from the fluorescent lamp 2 is not incident on the transmission / reception unit 51 of the Doppler sensor 5 even when reflected by the cover 4. The positional relationship is determined.

  In the following description, the first plane P1 that is a virtual plane including the surface (the lower surface in FIG. 1) facing the fluorescent lamp 2 and the Doppler sensor 5 in the cover 4, and the central axis O of the light emitting part of the fluorescent lamp 2 And a second plane P2 which is a virtual plane orthogonal to the first plane P1.

  First, the distance between the central axis O of the light emitting part of the fluorescent lamp 2 and the first plane P1 (that is, the distance to the cover 4) is hereinafter referred to as a reference distance d. In addition, a boundary line 52 that is a boundary line (contour) of the detection range in the cross section that includes the transmission / reception unit 51 of the Doppler sensor 5 and that is orthogonal to the central axis O of the light emitting unit of the fluorescent lamp 2 and that is close to the fluorescent lamp 2; Hereinafter, an angle formed by a perpendicular line from the transmission / reception unit 51 to the first plane P1 is referred to as a limit incidence θ.

  The radiation noise generated in the fluorescent lamp 2 may affect the Doppler sensor 5 because the radiation noise emitted from the fluorescent lamp 2 is incident on the transmitter / receiver 51 of the Doppler sensor 5 after being reflected by the cover 4. In this case, the incident angle is equal to or smaller than the angle θ. This condition is considered below.

  Let x be the distance between the transmitter / receiver 51 of the Doppler sensor 5 and the second plane P2, and let y be the distance between the transmitter / receiver 51 of the Doppler sensor 5 and the first plane P1. Then, as shown in FIG. 1, radiation noise that is emitted from the fluorescent lamp 2 in the tangential direction of the cross section of the light emitting portion and incident on the first plane P1 at a limit incident angle θ (0 <θ <90) is reflected. Let us consider expressing the position of the Doppler sensor 5 (hereinafter referred to as “limit incident position”) that is incident on the end closer to the fluorescent lamp 2 in the transmission / reception unit 51 by the above x and y. That is, when x is larger or y is smaller than the limit incident position, the radiation noise does not affect the operation of the Doppler sensor 5.

  Hereinafter, on the cross section orthogonal to the central axis O of the light emitting part of the fluorescent lamp 2 and including the transmission / reception part 51 of the Doppler sensor 5, a condition to be satisfied by the above x and y is obtained.

  First, let A be the intersection of the cross section, the first plane P1, and the second plane P2. Moreover, it is a tangent with respect to the cross section of the light emission part of the fluorescent lamp 2, Comprising: The direction of an inclination is a direction (right upward direction in FIG. 1) which approaches the 1st plane P1 toward the Doppler sensor 5, and the 1st plane P1 Of the tangents whose angle with the perpendicular is the limit incident angle θ, regarding the tangent closer to the transmitter / receiver 51 of the Doppler sensor 5, the intersection with the first plane P1 is set to Q, and the light emitting part of the fluorescent lamp 2 Let P be the contact point. That is, AO = d, and OP matches the radius r of the light emitting part of the fluorescent lamp 2.

  Then, the condition that x should satisfy is expressed as x> AQ + ytan θ.

  Furthermore, considering a third plane P3 that is a virtual plane that is parallel to the first plane P1 and includes the central axis O, the intersection of the third plane P3 and the tangent line is set to B, and Let C be the intersection of the perpendicular drawn from the point Q to the third plane P3 and the third plane P3. Then, from the similarity between the triangle QBC and the triangle OBP, the angle BOP is equal to the angle BQC, that is, the limit incident angle θ, and therefore the length of the line segment OB is expressed as r / cos θ. Therefore, AQ = OC = BC + OB = dtan θ + r / cos θ.

  By substituting this into x> AQ + ytan θ, in order to prevent radiation noise emitted from the fluorescent lamp 2 from entering the transmission / reception unit 51 of the Doppler sensor 5 at an incident angle equal to or smaller than the limit incident angle θ after being reflected by the cover 4, The condition to be satisfied is as follows.

  In other words, even if the fluorescent lamp 2 is arranged symmetrically with respect to the inner surface (first plane P1) of the cover 4, the fluorescent lamp 2, the cover 4, and the Doppler sensor 5 are arranged so as not to enter the detection range of the Doppler sensor 5. The positional relationship is determined.

  According to the above configuration, the radiation noise generated in the fluorescent lamp 2 does not enter the Doppler sensor 5 at least by one reflection at the cover 4, so that the radiation noise generated in the fluorescent lamp 2 does not easily enter the Doppler sensor 5.

  From the viewpoint of miniaturization, it is desirable that x is as small as possible within the above range.

  Further, in order to further suppress the influence of the cover 4 on the operation of the Doppler sensor 5, as shown in FIG. 2, the transmission / reception of the Doppler sensor 5 is seen from the thickness direction of the cover 4 (left-right direction in FIG. 2). At least a part of the part 51 does not overlap the cover 4 (that is, the transmission / reception part 51 of the Doppler sensor 5 as a whole is not covered by the cover 4 when viewed from the outside of the lighting fixture 1). It is desirable that the dimensions and the positional relationship between the cover 4 and the Doppler sensor 5 are determined.

  Furthermore, y> d in the example of FIG. 2 is attached to the wall surface 6 in such an orientation that the Doppler sensor 5 is positioned below the fluorescent lamp 2. Further, the arrangement of the Doppler sensor 5 in the axial direction of the light emitting part of the fluorescent lamp 2 (direction perpendicular to the paper surface in FIGS. 1 and 2) is, for example, near the central part in the axial direction of the light emitting part of the fluorescent lamp 2. Can be arranged. As described above, the positional relationship between the fluorescent lamp 2 and the Doppler sensor 5 can be appropriately changed in consideration of the design and the like within the range satisfying the above formula.

  As an example of specific numerical values of the dimensions of each part, the radius r of the light emitting part of the fluorescent lamp 2 is 13 mm, the reference distance d is 27 mm, the limit incident angle θ is 30 °, and between the first plane P1 and the transmitting / receiving part 51 When the distance y is 49 mm, the distance x between the second plane P2 and the transmission / reception unit 51 is 74 mm or more.

  Further, in order to suppress reflection at the cover 4, it is desirable that the thickness of the cover 4 be an integral multiple of a half wavelength of the radio wave transmitted by the Doppler sensor 5 in the cover 4. For example, when the material of the cover 4 is tempered glass having a relative dielectric constant of 6.2 and the frequency of the radio wave transmitted by the Doppler sensor 5 is 24.15 GHz (wavelength 12.4 mm), the half of the radio wave in the cover 4 is obtained. Since the wavelength is 12.4 / (2 · √6.2) ≈2.5 mm, the thickness of the cover 4 may be, for example, 5 mm, which is twice 2.5 mm.

DESCRIPTION OF SYMBOLS 1 Lighting fixture 2 Fluorescent lamp 4 Cover 5 Doppler sensor 51 Transmission / reception part (reception part)
52 boundary line O central axis P1 first plane P2 second plane

Claims (5)

A flat cover,
A straight tube type fluorescent lamp having a cylindrical light-emitting portion and disposed on one side in the thickness direction of the cover with the central axis of the light-emitting portion being parallel to the cover;
The receiving unit is disposed on the same side as the fluorescent lamp with respect to the first plane including the one side surface of the cover and receives a radio wave incident from a predetermined detection range including a part of the first plane. With a Doppler sensor,
A boundary line that is perpendicular to the central axis of the light emitting part of the fluorescent lamp and that is a boundary line of the detection range in a cross section that includes the receiving part and is closer to the fluorescent lamp, and a perpendicular line of the first plane An angle θ formed, a distance d between the central axis of the light emitting unit and the first plane, a radius r of the light emitting unit, a distance y between the first plane and the receiving unit, and a central axis of the light emitting unit. And the distance x between the second plane orthogonal to the first plane and the receiver is given by

A luminaire with a Doppler sensor characterized by satisfying the above condition.   2. The luminaire with a Doppler sensor according to claim 1, wherein at least a part of the Doppler sensor does not overlap the cover when viewed from the thickness direction of the cover.   The lighting apparatus with a Doppler sensor according to claim 1 or 2, wherein the Doppler sensor is disposed in the vicinity of a central portion in an axial direction of a light emitting portion of the fluorescent lamp.   It is y> d, The lighting fixture with a Doppler sensor of any one of Claims 1-3 characterized by the above-mentioned.   The lighting apparatus with a Doppler sensor according to any one of claims 1 to 4, wherein the Doppler sensor is used by being fixed so as to be positioned below the fluorescent lamp.

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